Forza 4 Interview: Turn 10 talks UGC, strain, and hints at tracks

Good news, everybody! Forza Motorsport 4 is the latest contender for the title …

A new installment of Microsoft's marquee car franchise, Forza Motorsport, is set to arrive in October. We've not had a chance to turn any laps in Forza Motorsport 4 yet, but in anticipation of a full review in the coming weeks, I spoke with Dan Greenawalt, Lead Game Designer at Turn 10, about the studio's latest arrival and the nuts and bolts of making a driving sim.

The Forza Motorsport franchise has been the Xbox 360's answer to Sony's Gran Turismo series. The first installment arrived in 2005 on the original Xbox, and Forza Motorsport 2 and Forza Motorsport 3 arrived at two-year intervals. The series has done a great many things to innovate the world of racing games, and that trend looks to continue in the newest release.

So, what goes into making a racing game?

One of the reason's for Forza's success has been its ever-evolving physics model. Drive an actual car on an actual track, and the information you're given through the steering wheel and the seat of your pants is the result of thousands of variables: the stiffness of the car's body, its mass (both of the whole thing and the unsprung bits), the amount of power to go and stop, the design and geometry of the suspension, the ever-changing relationship between the four tires and the track surface, and so on.

With over five hundred cars in the game, Turn 10 had to somehow turn all of that into data into something that you feel through a fancy steering wheel setup or the Xbox 360 controller to give the player the feeling of turning into a corner, of tires losing adhesion and beginning to spin, or of moments of inertia.

"We do have extensive information for example on the [Ferrari] Enzo," Greenawalt tells me. "By having the Enzo, and knowing the cars we are simulating, we're able to say 'this car's suspension geometry on the front is more similar to the Enzo than the Corvette,' for example."

They started with five cars, going as far as to take them apart to measure the several hundred points of research data, from simple things like weight distribution to measuring inertia on the driveline. Over the years more cars have been quantified, some to a greater degree than others. This has built up a database that provides the starting ground for each of the cars in the game.

Turn 10 doesn't use any data submitted by the manufacturers, who might not be above sending them a ringer. But their system is surprisingly accurate. "Even though we don't have the real numbers, we've actually been able to find errors in cars through this simulation," Greenawalt claims. All this work results in around 9,000 parameters for each car that are used by the game's physics engine to simulate everything from a tiny European hatchback to a Le Mans winning prototype racing car.

For Forza Motorsport 4, the team has thrown away all its previous tire data and started from scratch. Forza Motorsport 3 had data from Toyo, Michelin, Pirelli, and FAE, and it had to be manipulated so that it would all work together, despite being gathered at different testing facilities and with different testing methods. This time the game is built with new data: custom tests from Pirelli across a huge range of variables (tire height, width, compound, temperature, pressure, camber angle, etc) that was imported directly into the game. "That was the only way we saw to be as up-to-date as possible. We weren't copying the textbooks of racecar engineers from a couple of years ago but putting in the data that would write the textbooks of the coming years," Greenawalt explains.

This attention to detail shows up elsewhere too. Racing games have been getting better at recreating the sounds of cars, but usually only on full throttle. Now, as you build your cars up from shopping-spec to highly strung race monsters, you can expect backfires, burbles and pops on over run. Other aspects have also been worked on to add to the feeling of reality; cars sound different under load—up a hill on full throttle, say—"you can hear it straining, frankly," Greenawalt tells me.

User generated content

Forza Motorsport has been famous for the strength of its user-generated content, and it truly is amazing what some people are able to achieve with what seems like pretty basic image editing tools and a lot of layers. It's been a focus of the series for a long time, and that's set to continue in Forza Motorsport 4. Greenawalt is proud of what the livery editor has allowed gamers to achieve: "A lot of people want the tool to work like this, or work like that... we made a tool that was very powerful, but that doesn't mean that anyone can just go in and slap a texture on it. The important bit about that is we're creating a class of creative that's able to show off their skill with the tools."

One of Gran Turismo 5's new features was the introduction of a track editor, and I asked Dan if we might see anything like this in the future. Imagine being able to take GPS or Google Earth data of your favorite driving road, for example, and sharing it online. Sadly, this just isn't possible right now, mainly because of that perennial Ars topic, intellectual property (IP).

It's something they've considered. Greenawalt has spent time studying the various PC games and communities that have allowed it, and there's very little interest in anything other than virtual recreations of real tracks, both former and current: "Those are things that we really can't condone—the stealing of other people's IP. The first thing that gets made is Spa, or Bathurst, or Brands Hatch. When people make original tracks, they don't do well in these communities."

As to whether Spa or Bathurst or Brands Hatch will appear in the game, I was told enigmatically "we haven't announced all the tracks yet." Cue Internet speculation in 5, 4, 3

I also asked about whether we might see easier ways of getting user-generated content out of the game. Getting pictures out of GT5 is a lot easier than Forza Motorsport 3, as you can save them locally rather than having to upload them. Unfortunately, security concerns mean that Forzamotorsport.net will remain the portal for exporting images or movies from the game for now.

While we're on the subject of intellectual property, it is sadly true that Porsche will be absent from Forza Motorsport for the first time. Electronic Arts (EA) have an exclusive license with the Stuttgart manufacturer, and in the past has allowed Turn 10 to include them, but with their move towards a more sim-based game, the studio that everyone loves to hate has just given me another reason to curse their name. When asked if the German cars could reappear as DLC if EA relented, Greenawalt told me he's said everything he's really able to say on the matter, but the situation will be continually evaluated.

It's frustrating that digital rights issues have to raise their head, but they don't dampen my enthusiasm for the forthcoming game. It's due out in the US on October 11, which means I have to go out and find a Kinect in the next few weeks; for the head-turning, mind you, not the driving-with-no-steering-wheel. And it goes without saying, you'll be able to read a review of the game here at Ars.

52 Reader Comments

If you are a Jeremy Clarkson fan, the Porsche thing probably doesn't hurt much.

The circuits of Forza 3 felt very artificial, even circuits like Nurburgring lacked feeling. They seemed to be straightforward tarmac roads lacking any bumps whatsoever. Hopefully, the FM4 will be much better with the tracks. In comparison, F1 2010 did feel quite a bit more authentic to the circuit.

Well I for one have pre ordered. Really looking forward to this! Pity about EA and Porsche - maybe now Porsche (and other manufacturers) will think twice before signing an exclusive agreement with anyone.

Not that I even own a PS3, but is there any news on when GT6 is due? Yes yes I know everyone is going to say 2017, I'm just curious.

And if this is anything like the last 3 games its going to be all under steer and the only over steer will come when you hit the gas. Totally unrealistic especially after playing (working?) amazing simulations like Iracing.com

I've never been a Porsche fan, but I'm still lamenting over them not being included in the game. I don't want to *drive* them myself, but the experience will be lessened by not seeing them putting around the track with me. Previous to this I was starting to come back to the idea of EA being a "good" company again. Now though, they're my most hated company... *in the world!*

Well I for one have pre ordered. Really looking forward to this! Pity about EA and Porsche - maybe now Porsche (and other manufacturers) will think twice before signing an exclusive agreement with anyone.

Well they could have got more money from 2 deals as opposed to one, plus lots of positive PR. Some of the interviews stated that the manufacturers loved AutoVista mode because its a great way to show off their cars.

Lets not forget, this will keep Porsches out of any non EA racing games. That includes GT.

While I'm still more partial to the GT games, still am looking forward to playing Forza 4, if for no other reason than that it'll be nice to play a racing game where the UI doesn't punish you for playing.

I always thought the field of view in FM3 was poor. I much preferred the view in FM2 and because of that finished the game, and never came close to finishing FM3...minus the endurance races of course . Can't wait for FM4 though, really hoping for a track editor in a fun racing game one day. Used to make tracks in Motocross Madness via photoshop greyscale images, such a tedious process but the homebrew community has always been willing to put up with some inconvienence for the fun of actually getting to be creative and race (or fly as it were in moto madness...) on something you created. I'm thinking taking the 300 mile trip to my vacation home would be hella fun in a Veyron or McLaren F1...

.......Can't wait for FM4 though, really hoping for a track editor in a fun racing game one day. Used to make tracks in Motocross Madness via photoshop greyscale images, such a tedious process but the homebrew community has always been willing to put up with some inconvienence for the fun of actually getting to be creative and race (or fly as it were in moto madness...) on something you created. ...

TrackMania 2 Canyon? I think that is exactly what your looking for...

I remember the days of moto madness, that was a personal favorite of mine. I'm afraid to see how badly it has aged.

Articles like this makes me wish I could get into driving games. It just amazes me how much time, effort, and science goes into making these cars as accurate as possible. I've never been into cars in general but if this pattern of research keeps up I may breakdown and finally buy a racing game.

.......Can't wait for FM4 though, really hoping for a track editor in a fun racing game one day. Used to make tracks in Motocross Madness via photoshop greyscale images, such a tedious process but the homebrew community has always been willing to put up with some inconvienence for the fun of actually getting to be creative and race (or fly as it were in moto madness...) on something you created. ...

TrackMania 2 Canyon? I think that is exactly what your looking for...

I remember the days of moto madness, that was a personal favorite of mine. I'm afraid to see how badly it has aged.

I remember making my own tracks on Stunts. Remember Stunts? Wow, has gaming come a long way.

The loss of the Porsche license is a huge upset for Le Mans fans, as Forza's always had a decent lineup and F3 had the glorious 962c and the 911 GT1 spider/strassenversion. I was SO hoping for the 910/917 era Porsches to appear, or even Bellof's Nordschleife record-setting 956 and thanks to EA, it's no-go. :(

This had better be REALLY good for me to want to get it. I LOVE FM3, and still play it constantly. The only thing I really want are more and more tracks. Smaller ones. Sears Point, Mid Ohio, Watkins Glen, etc. The track editor would rock, because then I can re-create the local track that I know will never make it (BIR)

And if this is anything like the last 3 games its going to be all under steer and the only over steer will come when you hit the gas. Totally unrealistic especially after playing (working?) amazing simulations like Iracing.com

Nothing on any console, and very few (if any) on the PC are going to compare to iRacing.

With over five hundred cars in the game, Turn 10 had to somehow turn all of that into data into something that you feel through a fancy steering wheel setup or the Xbox 360 controller to give the player the feeling of turning into a corner, of tires losing adhesion and beginning to spin, or of moments of inertia.

Is that a press release exert or the writer's thoughts? Because if it's the latter, he should not write about simulators ever again. FM3 has a very simplistic physics model and the FFB modelling is mediocre. If you want to really feel proper FFB effects, try the Live for Speed demo on anything but a Trust or MS XBOX 360 wheel.

Well I for one have pre ordered. Really looking forward to this! Pity about EA and Porsche - maybe now Porsche (and other manufacturers) will think twice before signing an exclusive agreement with anyone.

Not that I even own a PS3, but is there any news on when GT6 is due? Yes yes I know everyone is going to say 2017, I'm just curious.

Polyphony have been pretty tight lipped about it, but it's likely to be on the PS4 and 2014+. GT5 still has content under development and while development of GT6 had started before GT5 had finished, I wonder how much in the way of resources it had when GT5 was rushed out the door in the end (so to speak). But I seriously wonder how much more could be done graphically on current gen consoles anyway, Sony would be best spending a couple of years re-rendering GT5 for a new console and getting all the graphics right, the rest of the game was pretty good in my eyes. Looks like Forza 4 is somewhere similar.

Nekojin wrote:

Uncompetative wrote:

Damn.

No Porsche. No sale.

So, because you're upset about EA's exclusivity license, you're going to "punish" Microsoft, who has no actual say in the matter. That makes sense.

I don't think this has anything to do with punishing, it's most likely because they're a Porsche fan. One of the great things about these games is to drive the cars you can never own.

With over five hundred cars in the game, Turn 10 had to somehow turn all of that into data into something that you feel through a fancy steering wheel setup or the Xbox 360 controller to give the player the feeling of turning into a corner, of tires losing adhesion and beginning to spin, or of moments of inertia.

Is that a press release exert or the writer's thoughts? Because if it's the latter, he should not write about simulators ever again. FM3 has a very simplistic physics model and the FFB modelling is mediocre. If you want to really feel proper FFB effects, try the Live for Speed demo on anything but a Trust or MS XBOX 360 wheel.

And if this is anything like the last 3 games its going to be all under steer and the only over steer will come when you hit the gas. Totally unrealistic especially after playing (working?) amazing simulations like Iracing.com

I'm not the biggest FM fan (prefer GT myself) but you do realize that the vast vast majority of cars, no matter how expensive, are setup to understeer in order to keep the driver from spinning it off into a tree when he takes a corner a little to briskly? Oversteer and snap oversteer are far more dangerous to the average untrained driver than understeer.

No sim is going to get it exactly right, but saying that the whole engine is flawed because it doesn't drive like Burnout Paradise is a little ignorant.

I'm not sure I get your point. Both FM3 and GT5 are far from being considered proper simulators and my subjective impression is that both use mostly canned FFB effects. I'm indeed questioning your expertise in simulators if you can make statements like those.

Articles like this makes me wish I could get into driving games. It just amazes me how much time, effort, and science goes into making these cars as accurate as possible. I've never been into cars in general but if this pattern of research keeps up I may breakdown and finally buy a racing game.

I had this issue for years where "actual driving" was so completely different to "computer driving" that I couldn't do (or enjoy) the latter at all.

Then came games with the "through the window" view, rather than the "looking down on the whole car" view. Suddenly, the information my eyes were getting bore at least some relationship to actual driving, and I could finally enjoy driving games!

I had a blast with both Forza 3, and also with GT5, although I have to say I put more hours into Forza 3 because basically I'd played it a fair bit in the year leading up to when GT5 finally dropped, so was a bit "raced out".

I'm not sure I get your point. Both FM3 and GT5 are far from being considered proper simulators and my subjective impression is that both use mostly canned FFB effects. I'm indeed questioning your expertise in simulators if you can make statements like those.

you use the word subjective then seem to ignore its meaning criticizing the author.

.......Can't wait for FM4 though, really hoping for a track editor in a fun racing game one day. Used to make tracks in Motocross Madness via photoshop greyscale images, such a tedious process but the homebrew community has always been willing to put up with some inconvienence for the fun of actually getting to be creative and race (or fly as it were in moto madness...) on something you created. ...

TrackMania 2 Canyon? I think that is exactly what your looking for...

I remember the days of moto madness, that was a personal favorite of mine. I'm afraid to see how badly it has aged.

I'm not sure I get your point. Both FM3 and GT5 are far from being considered proper simulators and my subjective impression is that both use mostly canned FFB effects. I'm indeed questioning your expertise in simulators if you can make statements like those.

It's not a subjective statement that Forza models tire physics, nor that the game interprets that data and communicates it to the player via haptic feedback. Even with the MS wireless wheel, but especially with a Fanatec wheel, you can feel the front tires light up as they exceed grip going into a turn. Whether or not it's as 100% accurate as iRacing is a different matter, but iRacing has a very specific niche audience (as do the other PC racing sims, most of which are now community supported). Forza has to appeal across the spectrum, from racing nerds like me to very casual gamers. But you cannot say that they don't do it, nor that their job is quantifying how different cars behave and then translate that into something the game can process.

I'm not sure I get your point. Both FM3 and GT5 are far from being considered proper simulators and my subjective impression is that both use mostly canned FFB effects. I'm indeed questioning your expertise in simulators if you can make statements like those.

@ferongrFM3 is fantastic with the Fanatec wheel. And yes, I have played iracing also.

I agree, I have played Forza 3, GT5, and tried IRacing with the Porsche wheel, and it is fantastic across all 3. FM3 is a little behind the other 2, but still feels fantastic. Disregarding the auto-steering that happens when counter-steering, the wheel experience is quite solid.

Which is why I questioned the gentleman who questioned the article writer. Has he played all of these games with the same wheel across multiple titles? It begged to be asked.

god, I hate EA. they do so much wrong. besides the Porsche thing, I hate how quickly they retire their game servers, making a lot of their games obsolete. They retire much much much much faster than any other game company, perhaps all the game companies combined.